/***********************************************************************
 Freeciv - Copyright (C) 1996 - A Kjeldberg, L Gregersen, P Unold
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
***********************************************************************/
#ifndef FC__FEATURED_TEXT_H
#define FC__FEATURED_TEXT_H

#include "shared.h"             /* bool type. */

#include "fc_types.h"

/*
 * Some words about the featured text module.
 *
 * Bored to have black only chat, players used to hack their clients, to
 * obtain colored chat based patterns.  Also for strategic communication,
 * they added some clickable links on particular city or location.
 * The present code is not based on old warclient code, but it also contains
 * the same tools.  Whereas colors where determinated in client side only,
 * here the server also has the possibility to choose what color to display
 * to the clients.  Such embellishments are performed using escape sequences
 * (which are described bellow) in the strings.
 *
 * Plain text vs featured text.
 *
 * What is called plain text in those files is actually a string without any
 * escape sequence.  It is the text which should basically displayed in the
 * client, without taking account of the features.  On the other side, what
 * is called featured text is also a string, but which could include one of
 * many escape sequences.
 *
 * Text tag.
 *
 * The text_tag type is a structure which tag a particular modification for
 * a string.  It contains many informations, which the type of modification,
 * the start of the modification in bytes from the start of the string, and
 * the stop of it.  It also can contains many others fields, according to
 * sequence type.
 * Note that all offset datas are calculated in bytes and not in character
 * number, so the client must translate those offsets before using them.
 *
 * Escape sequences.
 *
 * - Bold.
 * Full name sequence: [bold] ... [/bold]
 * Abbreviation sequence: [b] ... [/b]
 * Text tag type: TTT_BOLD
 *
 * - Italic.
 * Full name sequence: [italic] ... [/italic]
 * Abbreviation sequence: [i] ... [/i]
 * Text tag type: TTT_ITALIC
 *
 * - Strike.
 * Full name sequence: [strike] ... [/strike]
 * Abbreviation sequence: [s] ... [/s]
 * Text tag type: TTT_STRIKE
 * 
 * - Underline.
 * Full name sequence: [underline] ... [/underline]
 * Abbreviation sequence: [u] ... [/u]
 * Text tag type: TTT_UNDERLINE
 *
 * - Color.
 * Full name sequence: [color] ... [/color]
 * Abbreviation sequence: [c] ... [/c]
 * Text tag type: TTT_COLOR
 * Option: foreground (abbreviation fg): a color name or a hex specification
 * such as #3050b2 or #35b.
 * Option: background (abbreviation bg): same type of data.
 *
 * - Link.
 * Full name sequence: [link] ... [/link] or [link/]
 * Abbreviation sequence: [l] ... [/l] or [l/]
 * Text tag type: TTT_LINK
 * Option: target (abbreviation tgt): absolutely needed.  It is set to
 * "city" (then link type is TLT_CITY), "tile" (TLT_TILE) or "unit"
 * (TLT_UNIT).
 * Option: id: if target type is TLT_CITY or TLT_UNIT, it is the id of
 * the target.
 * Option: name: if target type is TLT_CITY or TLT_UNIT, it is an additional
 * string to display if the target is not known by the receiver.
 * Options: x and y: if target type is TLT_TILE, they are the coordinates
 * of the target.
 */

/* Offset type (in bytes). */
typedef int ft_offset_t;
/* Unset offset value. */
#define FT_OFFSET_UNSET ((ft_offset_t) -1)

/* Opaque type. */
struct text_tag;               

/* Define struct text_tag_list. */
#define SPECLIST_TAG text_tag
#define SPECLIST_TYPE struct text_tag
#include "speclist.h"           

#define text_tag_list_iterate(tags, ptag) \
  TYPED_LIST_ITERATE(struct text_tag, tags, ptag)
#define text_tag_list_iterate_end  LIST_ITERATE_END

/* The different text_tag types.
 * Chaning the order doesn't break the network compatiblity. */
enum text_tag_type {
  TTT_BOLD = 0,
  TTT_ITALIC,
  TTT_STRIKE,
  TTT_UNDERLINE,
  TTT_COLOR,
  TTT_LINK
};

/* The different text_tag link types.
 * Chaning the order doesn't break the network compatiblity. */
enum text_link_type {
  TLT_CITY,
  TLT_TILE,
  TLT_UNIT
};

/* Default maximal link size */
#define MAX_LEN_LINK    128

/* Simplification for colors. */
struct ft_color {
  const char *foreground;
  const char *background;
};

/**************************************************************************
  Builds a featured text color.
**************************************************************************/
static inline struct ft_color ft_color(const char *foreground,
                                       const char *background)
{
  struct ft_color color = {
    .foreground = foreground,
    .background = background
  };

  return color;
}

/**************************************************************************
  Returns whether a color is requested.
**************************************************************************/
static inline bool ft_color_requested(const struct ft_color color)
{
  return ((NULL != color.foreground && '\0' != color.foreground)
          || (NULL != color.background && '\0' != color.background));
}

/* Predefined colors. */
extern const struct ft_color ftc_any;

extern const struct ft_color ftc_warning;
extern const struct ft_color ftc_log;
extern const struct ft_color ftc_server;
extern const struct ft_color ftc_client;
extern const struct ft_color ftc_editor;
extern const struct ft_color ftc_command;
extern const struct ft_color ftc_changed;
extern const struct ft_color ftc_server_prompt;
extern const struct ft_color ftc_player_lost;
extern const struct ft_color ftc_game_start;

extern const struct ft_color ftc_chat_public;
extern const struct ft_color ftc_chat_ally;
extern const struct ft_color ftc_chat_private;

extern const struct ft_color ftc_vote_public;
extern const struct ft_color ftc_vote_team;
extern const struct ft_color ftc_vote_passed;
extern const struct ft_color ftc_vote_failed;
extern const struct ft_color ftc_vote_yes;
extern const struct ft_color ftc_vote_no;
extern const struct ft_color ftc_vote_abstain;

/* Main functions. */
size_t featured_text_to_plain_text(const char *featured_text,
                                   char *plain_text, size_t plain_text_len,
                                   struct text_tag_list *tags);
size_t featured_text_apply_tag(const char *text_source,
                               char *featured_text, size_t featured_text_len,
                               enum text_tag_type tag_type,
                               ft_offset_t start_offset,
                               ft_offset_t stop_offset,
                               ...);

/* Text tag list functions. */
void text_tag_list_clear_all(struct text_tag_list *tags);
struct text_tag_list *text_tag_list_dup(const struct text_tag_list *tags);

/* Text tag functions. */
struct text_tag *text_tag_new(enum text_tag_type tag_type,
                              ft_offset_t start_offset,
                              ft_offset_t stop_offset,
                              ...);
void text_tag_destroy(struct text_tag *ptag);

enum text_tag_type text_tag_type(const struct text_tag *ptag);
ft_offset_t text_tag_start_offset(const struct text_tag *ptag);
ft_offset_t text_tag_stop_offset(const struct text_tag *ptag);

/* Specific TTT_COLOR text tag type functions. */
const char *text_tag_color_foreground(const struct text_tag *ptag);
const char *text_tag_color_background(const struct text_tag *ptag);

/* Specific TTT_LINK text tag type functions. */
enum text_link_type text_tag_link_type(const struct text_tag *ptag);
int text_tag_link_id(const struct text_tag *ptag);

/* Tools. */
const char *city_link(const struct city *pcity);
const char *city_tile_link(const struct city *pcity);
const char *tile_link(const struct tile *ptile);
const char *unit_link(const struct unit *punit);
const char *unit_tile_link(const struct unit *punit);

#endif /* FC__FEATURED_TEXT_H */
